Minimally invasive valve replacement system

ABSTRACT

Methods and systems for minimally invasive replacement of a valve. The system includes a collapsible valve and anchoring structure, devices and methods for expanding the valve anchoring structure, adhesive means to seal the valve to the surrounding tissue, a catheter-based valve sizing and delivery system, native valve removal means, and a temporary valve and filter assembly to facilitate removal of debris material. The valve assembly comprises a valve and anchoring structure for the valve, dimensioned to fit substantially within the valve sinus.

FIELD OF THE INVENTION

The present invention relates to devices and systems for the replacementof physiological valves.

BACKGROUND OF THE INVENTION

The transport of vital fluids in the human body is largely regulated byvalves. Physiological valves are designed to prevent the backflow ofbodily fluids, such as blood, lymph, urine, bile, etc., thereby keepingthe body's fluid dynamics unidirectional for proper homeostasis. Forexample, venous valves maintain the upward flow of blood, particularlyfrom the lower extremities, back toward the heart, while lymphaticvalves prevent the backflow of lymph within the lymph vessels,particularly those of the limbs.

Because of their common function, valves share certain anatomicalfeatures despite variations in relative size. The cardiac valves areamong the largest valves in the body with diameters that may exceed 30mm, while valves of the smaller veins may have diameters no larger thana fraction of a millimeter. Regardless of their size, however, manyphysiological valves are situated in specialized anatomical structuresknown as sinuses. Valve sinuses can be described as dilations or bulgesin the vessel wall that houses the valve. The geometry of the sinus hasa function in the operation and fluid dynamics of the valve. Onefunction is to guide fluid flow so as to create eddy currents thatprevent the valve leaflets from adhering to the wall of the vessel atthe peak of flow velocity, such as during systole. Another function ofthe sinus geometry is to generate currents that facilitate the preciseclosing of the leaflets at the beginning of backflow pressure. The sinusgeometry is also important in reducing the stress exerted bydifferential fluid flow pressure on the valve leaflets or cusps as theyopen and close.

Thus, for example, the eddy currents occurring within the sinuses ofValsalva in the natural aortic root have been shown to be important increating smooth, gradual and gentle closure of the aortic valve at theend of systole. Blood is permitted to travel along the curved contour ofthe sinus and onto the valve leaflets to effect their closure, therebyreducing the pressure that would otherwise be exerted by direct fluidflow onto the valve leaflets. The sinuses of Valsalva also contain thecoronary ostia, which are outflow openings of the arteries that feed theheart muscle. When valve sinuses contain such outflow openings, theyserve the additional purpose of providing blood flow to such vesselsthroughout the cardiac cycle.

When valves exhibit abnormal anatomy and function as a result of valvedisease or injury, the unidirectional flow of the physiological fluidthey are designed to regulate is disrupted, resulting in increasedhydrostatic pressure. For example, venous valvular dysfunction leads toblood flowing back and pooling in the lower legs, resulting in pain,swelling and edema, changes in skin color, and skin ulcerations that canbe extremely difficult to treat. Lymphatic valve insufficiency canresult in lymphedema with tissue fibrosis and gross distention of theaffected body part. Cardiac valvular disease may lead to pulmonaryhypertension and edema, atrial fibrillation, and right heart failure inthe case of mitral and tricuspid valve stenosis; or pulmonarycongestion, left ventricular contractile impairment and congestive heartfailure in the case of mitral regurgitation and aortic stenosis.Regardless of their etiology, all valvular diseases result in eitherstenosis, in which the valve does not open properly, impeding fluid flowacross it and causing a rise in fluid pressure, orinsufficiency/regurgitation, in which the valve does not close properlyand the fluid leaks back across the valve, creating backflow. Somevalves are afflicted with both stenosis and insufficiency, in which casethe valve neither opens fully nor closes completely.

Because of the potential severity of the clinical consequences of valvedisease, valve replacement surgery is becoming a widely used medicalprocedure, described and illustrated in numerous books and articles.When replacement of a valve is necessary, the diseased or abnormal valveis typically cut out and replaced with either a mechanical or tissuevalve. A conventional heart valve replacement surgery involves accessingthe heart in a patient's thoracic cavity through a longitudinal incisionin the chest. For example, a median sternotomy requires cutting throughthe sternum and forcing the two opposite halves of the rib cage to bespread apart, allowing access to the thoracic cavity and the heartwithin. The patient is then placed on cardiopulmonary bypass, whichinvolves stopping the heart to permit access to the internal chambers.Such open heart surgery is particularly invasive and involves a lengthyand difficult recovery period. Reducing or eliminating the time apatient spends in surgery is thus a goal of foremost clinical priority.

One strategy for reducing the time spent in surgery is to eliminate orreduce the need for suturing a replacement valve into position. Towardthis end, valve assemblies that allow implantation with minimal or nosutures would be greatly advantageous. Furthermore, while devices havebeen developed for the endovascular implantation of replacement valves,including collapsing, delivering, and then expanding the valve, suchdevices do not configure the valve in a manner that takes advantage ofthe natural compartments formed by the valve sinuses for optimal fluiddynamics and valve performance. In addition, to the extent that suchdevices employ a support structure in conjunction with a tissue valve,such valve constructs are configured such that the tissue leaflets ofthe support valve come into contact with the support structure, eitherduring the collapsed or expanded state, or both. Such contact is capableof contributing undesired stress on the valve leaflet. Moreover, suchsupport structures are not configured to properly support a tissue valvehaving a scalloped inflow annulus such as that disclosed in the U.S.patent application Ser. No. 09/772,526 which is incorporated byreference herein in its entirety.

Accordingly, there is a need for a valve replacement system comprising acollapsible and expandable valve assembly that is capable of beingsecured into position with minimal or no suturing; facilitating ananatomically optimal position of the valve; maintaining an open pathwayfor other vessel openings of vessels that may be located in the valvularsinuses; and minimizing or reducing stress to the tissue valve leaflets.The valves of the present invention may comprise a plurality of joinedleaflets with a corresponding number of commissural tabs. Generally,however, the desired valve will contain two to four leaflets andcommissural tabs. Examples of other suitable valves are disclosed inU.S. patent application Ser. Nos. 09/772,526, 09/853,463, 09/924,970,10/121,208, 10/122,035, 10/153,286, 10/153,290, the disclosures of allof which are incorporated by reference in their entirety herein.

SUMMARY OF THE INVENTION

The present invention provides systems and devices for the replacementof physiological valves. In one embodiment of the present invention, thereplacement valve assemblies are adapted to fit substantially within thevalve sinuses. Because the devices and procedures provided by thepresent invention eliminate or reduce the need for suturing, time spentin surgery is significantly decreased, and the risks associated withsurgery are minimized. Further, the devices of the present invention aresuitable for delivery by cannula or catheter.

In one preferred embodiment of the present invention a valve anchoringstructure is provided that is dimensioned to be placed substantiallywithin the valve sinus. In this embodiment, the valve anchoringstructure extends substantially across the length of the valve sinusregion.

In another preferred embodiment of the present invention a valveassembly is provided, comprising a valve and anchoring structure, inwhich the valve comprises a body having a proximal end and a distal end,an inlet at the proximal end, and an outlet at the distal end. The inletcomprises an inflow annulus, preferably with either a scalloped orstraight edge. The outlet comprises a plurality of tabs that aresupported by the anchoring means at the distal end. In preferredembodiments of the invention, the plurality of tabs are spaced evenlyaround the circumference of the valve.

In yet another embodiment of the present invention, a valve assembly isprovided in which there is minimal or no contact between the valve andanchoring structure.

In still another embodiment of the present invention, a valve assemblyis provided in which the valve is capable of achieving full opening andfull closure without contacting the anchoring structure.

In yet another embodiment of the present invention, a valve assembly isprovided in which the vertical components of the anchoring structure arelimited to the commissural posts between sinus cavities, therebyminimizing contact between mechanical components and fluid, as well asproviding flow to vessels located in the valve sinus.

In still another embodiment of the present invention, a valve isprovided that firmly attaches to the valve sinus, obviating the need forsuturing to secure the valve placement.

In a further embodiment of the present invention, a valve assembly isprovided in which the anchoring structure may be collapsed to at leastfifty percent of its maximum diameter.

In still a further embodiment of the present invention, an expansion andcontraction device is provided to facilitate implantation of the valveand anchoring structure.

In another embodiment, the present invention provides adhesive means forsecuring the valve assembly in a valve sinus.

In yet another embodiment of the present invention, a valve sizingapparatus is provided for the noninvasive determination of native valvesize.

The present invention also provides cutting means to remove the nativediseased valve. One aspect of the cutting means comprises a plurality ofjaw elements, each jaw element having a sharp end enabling the jawelement to cut through at least a portion of the native valve. Anotheraspect of the cutting means comprises a plurality of electrode elements,wherein radiofrequency energy is delivered to each electrode elementenabling the electrode element to cut through at least a portion of thenative valve. A further aspect of the cutting means comprises aplurality of ultrasound transducer elements, wherein ultrasound energyis delivered to each transducer element enabling the transducer elementto cut through at least a portion of the native valve.

In yet another embodiment, the present invention provides a temporarytwo-way valve and distal protection filter assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary valve during operation. FIG. 1A shows thevalve in the open position during peak flow. FIG. 1B shows the valve inclosed position to prevent backflow of the fluid across the valve.

FIG. 2 shows a preferred embodiment of the valve of the presentinvention. This valve features commissural tabs and a scalloped inflowannulus.

FIGS. 3A, B and C are representations of a typical valve sinus. Thesefigures illustrate the anatomy of the sinus cavities, commissural posts,leaflets and inflow/outflow annuli.

FIG. 4 is a schematic representation of the geometry and relativedimensions of the valve sinus region.

FIG. 5 shows a valve anchoring structure, in accordance with a preferredembodiment of the present invention, that is lodged inside a vessel.

FIGS. 6A and B are schematics of a valve assembly comprising a valve andan anchoring structure in which the anchoring structure features anadditional cloth ring along the valve inflow edge that serves as agasket. FIG. 6C shows a valve anchoring structure according to onepreferred embodiment of the present invention featuring a two-ringinflow rim.

FIG. 7 is a diagrammatic representation of a flat pattern of a preferredembodiment of an anchoring structure in the expanded state.

FIG. 8 is a diagrammatic representation of a flat pattern of a preferredembodiment of an anchoring structure in the compressed state.

FIG. 9 shows a flat valve leaflet of a preferred valve to which theanchoring structure dimensions can be fitted.

FIG. 10 illustrates the relative dimensions of a preferred embodiment ofan anchoring structure of the present invention.

FIG. 11 shows a flared anchoring structure dimensioned to lodge insidethe sinus cavities.

FIG. 12 shows a different view of the flared anchoring structure.

FIG. 13 shows a preferred embodiment of an anchoring structure lackingan outflow ring, and having support posts dimensioned to lodge in thesinus commissural posts, providing cantilevered support for the valveoutflow end.

FIG. 14 shows a preferred embodiment of an anchoring structure withflared in- and outflow ends and support posts for lodging in thecommissural posts with attachment windows capable of deflecting inwardat back flow pressure.

FIG. 15A shows a top view of a preferred embodiment of a valve assemblycomprising a valve and an anchoring structure made of ellipticalsegments joined together. FIG. 15B shows a lateral view of the preferredanchoring structure without valve.

FIG. 16A shows the valve assembly comprising a valve and ellipticalsegment anchoring structure in expanded form. FIG. 16B shows the same incompressed form

FIG. 17 shows the lodging of an elliptical anchoring structure insidethe valve sinus cavities.

FIG. 18A shows how the elliptical segments of the anchoring structuremay be joined by a double crimp. FIG. 18B shows how the valve ispositioned inside the anchoring structure.

FIG. 19A shows a double crimp uniquely designed to flexibly join theelliptical segments. FIG. 19B shows a modified double crimp.

FIG. 20A shows how the elliptical segments may be assembled into thedouble crimp. FIG. 20B shows the final assembly.

FIGS. 21A-G show different views of an elliptical segment anchoringstructure further comprising cloth covering including a gasket clothcuff at the inflow rim.

FIGS. 22A and B show different views of an elliptical segment anchoringstructure made from a single piece of tubing.

FIGS. 23A through D show an elliptical segment anchoring structure inwhich the upper segments have been removed and the ends of the junctionsare formed into prongs.

FIG. 24 shows a preferred valve assembly of the present invention withan anchoring structure comprising a ring incorporated into the valveinflow rim.

FIG. 25A shows an anchoring structure comprising two undulating ringswith inverse wave patterns. FIG. 25B shows an anchoring structurecomprising two such rings connected by vertical elements.

FIG. 26 shows a valve assembly comprising an anchoring structure inwhich the inflow ring and outflow ring are structurally unconnected.

FIG. 27A-C show a tubular anchoring structure.

FIGS. 28A-D show an anchoring structure comprising an inflow ring and anoutflow ring connected by vertical posts that slide across one anotherupon compression.

FIGS. 29A and B show an anchoring structure comprising an inflow andoutflow ring connected by vertical posts that join to form a singlevertical element upon compression.

FIGS. 30A and B shows an anchoring structure comprising a three-memberspring aided frame.

FIGS. 31A and B show a preferred embodiment of an expansion andcontraction device.

FIGS. 32A and B more particularly shows the angled wires of the device.

FIG. 33 shows the positioning of an anchoring structure on the expansionand contraction device.

FIG. 34 shows another preferred embodiment of an expansion andcontraction device featuring a wire-spindle mechanism.

FIG. 35 shows a different perspective of the wire-spindle expansion andcontraction device.

FIGS. 36A and B show another preferred embodiment of an expansion andcontraction device for self-expanding valve assemblies.

FIG. 37A shows a further preferred embodiment of an expansion andcontraction device featuring a rotating plate mechanism. FIGS. 37B and Cmore particularly shows the spiral-shaped rotating plate.

FIGS. 38A and B show the expansion and contraction device expanding ananchoring frame.

FIG. 39 shows another preferred embodiment of an expansion andcontraction device featuring a groove-pin mechanism.

FIG. 40 shows one preferred embodiment of a valve having an outercircumferential reservoir containing a sealable fixation means forsecurely fixing the valve prosthesis at a desired location within avessel or body cavity.

FIGS. 41A and B show another embodiment of a valve having an outercircumferential reservoir, wherein the sealabe fixation means comprisesa two component biological adhesive.

FIG. 42 illustrates a reservoir with thin spots adapted to rupture whenthe reservoir is under pressure, thereby releasing the contents of thereservoir.

FIG. 43 is a cross-sectional view of the reservoir showing the thinspots.

FIG. 44 is a cross-sectional view of a valve reservoir having twoconcentric component compartments.

FIGS. 45A and B depict a minimally-invasive valve replacement sizer.

FIG. 46 is a cross-sectional view of a minimally-invasive valvereplacement sizer comprising a guidewire, an intravascular ultrasound(IVUS) catheter having a transducer, and a balloon catheter, allpositioned within the central lumen of the catheter.

FIG. 47 shows a balloon catheter comprising a balloon thatcircumferentially surrounds a portion of the catheter at its distalportion.

FIG. 48 shows a cross-sectional view of an inflated balloon with curvesforming leaflets to enable fluid to pass.

FIG. 49 shows one preferred embodiment of a minimally-invasive valvereplacement sizer, wherein the balloon is inflated with saline.

FIG. 50 shows a preferred embodiment of a minimally-invasive valvereplacement sizer system, wherein the transducer emits an ultrasonicsignal in a perpendicular direction to an intravascular ultrasoundcatheter (IVUS), which is reflected off the outer wall of the balloonand then received by the transducer and wherein the radius and diameterof the body cavity is determined by the auxiliary processor.

FIG. 51 shows an anchoring structure of the present invention havingultrasound cutting means.

FIG. 52 shows an anchoring structure of the present invention havingradiofrequency cutting means.

FIG. 53 shows an anchoring structure having sharp edge cutting means.

FIG. 54 is a partial view of the valve assembly with cutting means on apartially inflated balloon catheter.

FIGS. 55A-C show a temporary two-way valve for distal protection.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to valve replacement systems and devices.As illustrated in FIG. 1, a valve (1) comprises a distal or outflow end(2), leaflets (3) and a proximal or inflow end (4). A typical valvefunctions similar to a collapsible tube in that it opens widely duringsystole or in response to muscular contraction, to enable unobstructedforward flow across the valvular orifice (FIG. 1A). In contrast, at theend of systole or contraction, as illustrated in FIG. 1B, as forwardflow decelerates, the walls of the tube are forced centrally between thesites of attachment to the vessel wall and the valve closes completely.

Replacement Valves

A preferred valve (5) for use with the systems and devices of thepresent invention is illustrated in FIG. 2 and is comprised of a bodyhaving a proximal end or inflow ring (6) and a distal end or outflowring (7). The body is comprised of multiple leaflets of valve tissuejoined by seams (8), wherein each seam is formed by a junction of twoleaflets. A commissural tab region (9) extends from each seam at thedistal end of the valve body. The proximal end (6) has an inflow ringwith a peripheral edge that can be scalloped or straight. The inflowring (6) of the valve can further comprise a reinforcement structure(10) that can be stitched to it. In preferred embodiments of theinvention, the inflow edge of the valve is scalloped. The valvereplacement systems and devices of the present invention are notlimited, however, to the specific valve illustrated in FIG. 2. Animportant consideration in the design of valve replacement systems anddevices that has received insufficient attention in previous approachesis the architecture of valve sinus. Valve sinuses are dilations of thevessel wall that surround the natural valve leaflets. Typically, eachnatural valve leaflet has a separate sinus bulge or cavity that allowsfor maximal opening of the leaflet at peak flow without permittingcontact between the leaflet and the vessel wall. Thus, for example, atwo-leaflet valve is surrounded by two sinus bulges, a three-leafletvalve by three, and a four-leaflet valve by four sinus cavities. Theindividual sinus bulges or cavities are separated by vertical fibrousstructures known as commissural posts. These commissural posts definelongitudinal structures with lesser outward curvature than the sinuscavities, as can be seen in FIG. 3. FIGS. 3A and B illustrate thereduced curvature of the commissural posts (11) compared with thecurvature of the sinus cavities (12). FIG. 3C shows a view from outsidethe vessel of a commissural post (11) between two sinus cavities (12),while FIG. 3A shows a cross sectional view from the top of a closedvalve within a valve sinus. The areas between the bulges define thecommissural posts (11) and as can be clearly seen in FIG. 3B, thecommissural posts serve as the sites of attachment for the valveleaflets to the vessel wall (13).

FIGS. 3B and C also show the narrowing diameter of the sinus region atboth its inflow end (14) and outflow end (15) to form the inflow andoutflow annuli of the sinus region. Thus, the valve sinuses form anatural compartment to support the operation of the valve by preventingcontact between the leaflets and the vessel wall, which, in turn, maylead to adherence of the leaflets and/or result in detrimental wear andtear of the leaflets. The valve sinuses are also designed to share thestress conditions imposed on the valve leaflets during closure whenfluid pressure on the closed leaflets is greatest. The valve sinusesfurther create favorable fluid dynamics through currents that soften anotherwise abrupt closure of the leaflets under conditions of highbackflow pressure. Lastly, the sinuses ensure constant flow to anyvessels located within the sinus cavities.

As shown in FIG. 4, the valve sinus region is characterized by certainrelative dimensions which remain constant regardless of the actual sizeof the sinuses. Generally, the diameter of the sinus is at its largestat the center of the cavities or bulges (16), while there is pronouncednarrowing of the sinus region at both the inflow annulus (17) andoutflow annulus (18). Furthermore, the height of the sinus (19), i.e.the distance between the inflow and outflow annuli remains proportionalto its overall dimensions. It is thus apparent that the sinus regionforms an anatomical compartment with certain constant features that areuniquely adapted to house a valve. The systems and devices of thepresent invention are designed to utilize these anatomical features ofthe native sinus region for optimal replacement valve function andposition.

Accordingly, in one preferred embodiment of the present invention, thereplacement valve assembly comprises a collapsible and expandableanchoring structure adapted to support a valve distally along thecommissural tab region and proximally along the inflow annulus. FIG. 5shows a preferred anchoring structure adapted to support a valve such asthat illustrated in FIG. 2. As seen in FIG. 5, the preferred anchoringstructure has a generally tubular configuration within which the valveis secured. The valve is secured at its proximal (inflow) annulus byattachment to the inflow rim (20) of the anchoring structure and at itsdistal end via the commissural tabs that are threaded through theaxially extending slots (21), which are formed in the support posts (22)that extend longitudinally from the inflow rim (20) to the outflow rim(23) of the anchoring structure. Thus, the distal ends (24) of thesupport posts contact the outflow rim (23) of the anchoring structure,whereas the proximal ends (25) of the support posts contact the inflowrim (20) of the anchoring structure.

In FIG. 5 the outflow rim (23) of the anchoring structure is depicted ascomprising a plurality of rings that extend between the support posts(22) generally at or above the axially extending slots (21) that residetherein. The plurality of rings of the outflow rim (23) are configuredin an undulating or zigzag pattern forming peaks (26) and valleys (27),wherein the individual rings remain substantially parallel to oneanother. The plurality of rings of the outflow rim comprise a verticalconnector element (28) positioned at the center of the valleys (27)formed by the undulating or zigzag pattern. This vertical connectorelement (28) is designed to stabilize the anchoring structure and toprevent distortion of the valve during compression and expansion of theanchoring structure comprising the valve. The vertical element (28)extends longitudinally in the axial direction of the cylindricalanchoring structure. In a preferred embodiment, the outflow rim (23) ofthe anchoring structure comprises two rings. In a preferredimplementation of this embodiment shown in FIG. 5, the inflow rim (20)of the support structure comprises a single ring that extends betweenthe support posts (22).

Both the inflow (20) and outflow (23) rims of the anchoring structureare formed with an undulating or zigzag configuration, although theinflow rim (20) may have a shorter wavelength (circumferential dimensionfrom peak to peak) and a lesser wave height (axial dimension from peakto peak) than the outflow rim (23). The wavelengths and wave heights ofthe inflow (20) and outflow (23) rims are selected to ensure uniformcompression and expansion of the anchoring structure without distortion.The wavelength of the inflow rim (20) is further selected to support thegeometry of the scalloped inflow annulus of a preferred valve of thepresent invention. Notably, as shown in FIG. 5, the undulating or zigzagpattern that forms the inflow rim (20) of the anchoring structure isconfigured such that the proximal ends (25) of the vertical supportposts (22) are connected to the peaks (29) of the inflow rim (20).Similarly, the undulating or zigzag pattern that forms the outflow rim(23) of the anchoring structure is configured such that the distal ends(24) of the support posts (22) are connected to the valleys (27) of theoutflow rim (23). Locating the distal ends (24) of the support posts atthe valleys (27) of the outflow rim (23) will prevent the longitudinalextension of outflow rim (23) in the direction of the valve securedwithin the lumen of the anchoring structure upon compression of thevalve assembly, thereby eliminating any contact between valve andanchoring structure. Likewise, locating the proximal ends (25) of thesupport posts at the peaks (29) of the inflow rim (20) will preventlongitudinal extension of the inflow rim (20) in the direction of thevalve tissue. Thus, compression of the valve and anchoring structuredoes not lead to distortion of or injury to the valve.

FIG. 5 further shows that the support posts (22) are configuredgenerally in the shape of paddle with the axial slot (21) extendinginternally within the blade (30) of the paddle. The blade (30) of thepaddle is oriented toward the outflow rim (23) of the anchoringstructure and connects to the outflow rim (23) at a valley (27) of theundulating or zigzag pattern of the outflow rim (23). An importantfunction of the support posts (22) is the stabilization of the valve ingeneral, and in particular the prevention of any longitudinal extensionat points of valve attachment to preclude valve stretching or distortionupon compression of the device. The blades (30) of the paddle-shapedsupport posts (22) are designed to accommodate the commissural tabs ofthe valve. The support posts (22) further comprise triangular shapedelements (31) extending on each side of the proximal end (25) of thesupport post. The triangular shaped elements (31) are designed to serveas attachments sites for the sewing cuff gasket and may be designed indifferent shapes without losing their function.

The number of support posts (22) in this preferred embodiment can rangefrom two to four, depending on the number of commissural posts presentin the valve sinus. Thus, in a preferred embodiment, the anchoringstructure comprises three support posts for a three-leaflet valve with asinus that features three natural commissural posts. The support posts(22) of the anchoring structure are configured to coincide with thenatural commissural posts of the sinus.

FIGS. 6A and B show the preferred embodiment of FIG. 5 having a valvesecured internally. The valve (32) is secured at its proximal (inflow)annulus (33) by attachment to the inflow rim (20) of the anchoringstructure and at its outflow or distal end (34) via the commissural tabs(35) that are threaded through the axially extending slots (21), whichare formed in the support posts (22) that extend longitudinally from theinflow rim (20) to the outflow rim (23) of the anchoring structure.Notably, as can be seen in FIGS. 6A and B, in this preferred embodimentthe outflow rim (23) of the anchoring structure is configured to belongitudinally displaced from the distal outflow annulus (34) of thevalve leaflets (36) that reside within the lumen of the tubularanchoring structure, thereby avoiding any contact between the valveleaflets (36) and the anchoring structure.

As shown in FIGS. 6A and B, the inflow rim (20) of the anchoringstructure can be secured to the proximal inflow annulus (33) of thevalve via a suitable fabric that may be wrapped around thecircumferential juncture at the inflow end (33) and stitched intoposition to form a sewing cuff (37). The fabric may be made of anysuitable material including but not limited to woven polyester, such aspolyethylene terepthalate, polytetrafluoroethylene (PTFE), or otherbiocompatible material. Thus, the valve (32) is secured inside theanchoring structure by sewing a fabric ring (37) around the inflow rim(20) of the anchoring structure so as to create a sealing surface aroundthe outer perimeter of valve's inflow annulus (33). In a preferredembodiment, the fabric ring (37) comprises two sewing cuff rings asshown in FIGS. 6A and B, with the second sewing cuff ring (38) having alarger diameter than the inflow annulus of the native valve sinus toensure the firm lodging of the anchoring structure against the inflowannulus of the native valve sinus, thereby creating a tight, gasket-likeseal.

The positioning of the valve (32) internally to the preferred anchoringstructure with only the fabric of the commissural mounting tabs (35) ofthe valve (32) contacting the support posts (22) at the distal outflowannulus of the valve (34), while the proximal inflow annulus (33) of thevalve is separated from the inflow rim (20) of the anchoring structureby the sewing cloth (37), ensures that no part of the valve (32) iscontacted by the anchoring structure during operation of the valve (32),thereby eliminating wear on the valve (32) that may be occasioned bycontact with mechanical elements.

In FIGS. 6A, B and C the outflow rim (23) of the anchoring structure isdepicted as comprising a plurality of rings that extend between thesupport posts (22) generally at or above the axially extending slots(21) that reside at their distal ends (24). The plurality of rings ofthe outflow rim (23) are configured in an undulating or zigzag patternforming peaks (26) and valleys (27), wherein the individual rings remainsubstantially parallel to one another. The plurality of rings of theoutflow rim comprise a vertical connector element (28) positioned at thecenter of the valleys (27) formed by the undulating or zigzag pattern.This vertical connector element (28) is designed to stabilize theanchoring structure and to prevent distortion of the valve duringcompression and expansion of the anchoring structure containing thevalve within. The vertical element (28) extends longitudinally in theaxial direction of the cylindrical anchoring structure. In a preferredembodiment, the outflow rim of the anchoring structure comprises tworings.

FIG. 6C shows another implementation of a preferred anchoring structureof the present invention. In contrast to the implementation shown inFIG. 5, wherein the inflow rim (20) of the anchoring structure comprisesa single ring that extends between the support posts (22), theimplementation shown in FIG. 6C features an inflow rim (20) comprisingtwo rings that are substantially parallel to each other and areconnected by a vertical connector element (39) positioned at the centerof the peaks (29) formed by the undulating or zigzag pattern. Thisvertical connector element (39) is designed to stabilize the anchoringstructure and to prevent distortion of the valve during compression andexpansion of the anchoring structure comprising the valve. The verticalelement (39) extends longitudinally in the axial direction of thecylindrical anchoring structure. FIG. 6C also shows that the distal end(24) of the support post (22) may further comprise suture bores (41) tofacilitate the placement of additional sutures for the securing thevalve to the anchoring structure.

Because the wavelengths and wave heights of the inflow (20) and outflowrims (23) are selected to ensure uniform compression and expansion ofthe anchoring structure without distortion, a different wavelength andheight may be chosen for the inflow ring (20) of an implementation of apreferred embodiment of an anchoring structure featuring an inflow rim(20) with two substantially parallel undulating rings as shown in FIG. 6C. Thus, the inflow rim (20) depicted in FIG. 6C may have substantiallythe same wavelength and height as the outflow rim (23). Similarly, thesupport posts (22) may be modified to comprise a widened proximal end(25) with an axial slot (40) extending longitudinally from the inflowrim (20) toward the distal end (24) of the support posts (22) andcentrally through the triangular shaped elements (31). The widening ofthe proximal end (25) of the support posts (22) protects the triangularshaped elements (31) from distortion by the different collapsed profileof the inflow rim (20) with larger wavelength and height and ensuresthat no part of the valve (32) will be contacted by the anchoringstructure during compression.

FIGS. 7 and 8 show the expansion (FIG. 7) and compression (FIG. 8)profile of a preferred anchoring structure of the present invention. Ina preferred embodiment of the present invention, the anchoring structureis collapsible to at least 50% of its expanded diameter. As shown inFIGS. 7 and 8, the undulating or zigzag pattern that forms the inflowrim (20) of the anchoring structure is configured such that the proximalends (25) of the vertical support posts (22) are connected to the peaks(29) of the inflow rim (20). Similarly, the undulating or zigzag patternthat forms the outflow rim (23) of the anchoring structure is configuredsuch that the support posts (22) are connected to the valleys (27) ofthe outflow rim (23). Locating the distal ends (24) of the support posts(22) at the valleys (27) of the outflow rim (23) will prevent thelongitudinal extension of outflow rim (23) in the direction of the valveupon compression of the device, thereby eliminating any contact betweenvalve and anchoring structure. Similarly, locating the proximal ends(25) of the support posts (22) at the peaks (29) of the inflow rim (20)prevents structural interference between the proximal ends (25) of thesupport posts (22), in particular the triangular shaped elements (31)designed to support the scalloped inflow annulus of the replacementvalve, and the undulating pattern of the inflow rim (20), as well aslongitudinal extension of the inflow rim (20) in the direction of thevalve tissue. Thus, compression of the valve and anchoring structuredoes not lead to distortion of or injury to the valve.

FIG. 8 shows that the support posts (22) connect to the outflow rim (23)at a valley (27) of the undulating or zigzag pattern and that duringcompression, the support posts stabilize the anchoring structure bypreventing any longitudinal extension at points of valve attachment,that is at the proximal (25) and distal (24) ends of the support posts.The commissural mounting tabs of the valve are attached to the anchoringstructure by extending through the axial slots (40) of the support poststo the exterior of the anchoring structure, while the inflow annulus ofthe valve is connected to the inflow rim (20) of the anchoring structurevia a fabric ring. This arrangement allows firm attachment of the distalor outflow end of valve to the anchoring structure and ensures theproper positioning of the valve, with the outflow end being supportedsuch that the leaflets are allowed to open and close with the movementof fluid across the lumen of the valve. It should be noted that theparticular shapes of the individual elements of the structures disclosedherein may be modified by a person of skill in the art to achieve theadvantages described without departing from the scope of the presentinvention.

The number of support posts (22) in this preferred embodiment can rangefrom two to four, depending on the number of commissural posts presentin the valve sinus. Thus, in a preferred embodiment, the anchoringstructure comprises three support posts (22) for a three-leaflet valvewith a sinus that features three natural commissural posts. The supportposts (22) of the anchoring structure are configured to coincide withthe natural commissural posts of the sinus.

An advantage of this arrangement is the additional option for thesurgeon of suturing the valve assembly into place, wherein the anchoringstructure provides the surgeon with additional guidance as to the properanatomical positioning of the valve inside the native valve sinuses.Since the anchoring structure is dimensioned to fit precisely into thevalve sinus cavities, the surgeon's positioning task is simplified to avisual determination of the location of the commissural posts of thenative sinuses and their alignment with the support posts (22) of theanchoring structure of the valve. Thus, the present preferred embodimenttakes advantage of the natural features of the valve sinus for the rapidorientation and attachment of the valve assembly. The ability of theanchoring structure to emulate the architecture of the valve sinus thussignificantly reduces the surgeon's time spent on suturing the valveinto position, should he so desire.

The geometry of the preferred embodiment of a valve anchoring structurefurther naturally positions it across the entire longitudinal extensionof the native valve sinus, lodging the anchoring structure firmlyagainst the vessel walls. Proximally, the inflow rim (20) of theanchoring structure naturally fits into the native valve sinus at aposition near the inflow narrowing (annulus) of the native valve sinusagainst which it is designed to rest, while distally, the outflow rim(23) of the anchoring structure fits into the sinus at a position nearthe outflow narrowing (annulus) of the sinus against which it isdesigned to rest.

Between the proximal and distal ends of the anchoring structure the onlylongitudinal mechanical elements of the anchoring structure are thesupport posts (22) which are confined to the native commissural postsbetween the sinuses, leaving the sinus cavities free to create thenative fluid currents that support leaflet closure and valve operationin general. A further advantage of this preferred embodiment of thepresent invention is the ability of the anchoring structure to emulatethe natural compartment formed by the sinus for anchoring the valve.Thus, the anchoring structure is able to extend completely across thesinuses without placing mechanical elements into the path of fluid flowand without obstructing flow to any vessel openings that may be presentin the valve sinuses.

In a preferred implementation of the present embodiment, the anchoringstructure exerts radial force against the vessel wall so as to produce acompression fit. This may be accomplished by oversizing the anchoringstructure such that it permanently seeks to expand to its original size.Thus, both the inflow (20) and outflow (23) rims are designed to pushradially against the sinus walls near the inflow and outflow annuli ofthe sinus. The undulating or zigzag pattern formed by the inflow (20)and outflow (23) rings further serves to provide tire-like tractionagainst the sinus wall for anchoring. Thus, the combination ofcompression fit, traction and sewing cuff rings (37 and 38) of theanchoring structure provides a firm anchor for the replacement valve andan optimal configuration in the native valve sinus.

In preferred embodiments of the present invention, the anchoringstructure comprises a material that is expandable from a compressedconfiguration illustrated in FIG. 8 into the configuration depicted inFIG. 7. The anchoring structure may be non-self expanding, i.e. capableof being expanded from a compressed state using mechanical means, suchas a balloon inflated from within the radial center of the anchoringstructure, or using the expansion and compression devices disclosedherein. The anchoring structure comprises vertical tab support posts(22) which are designed to prevent inelastic deformation when theanchoring structure is collapsed prior to implantation.

FIG. 9 shows a representative flat valve leaflet (36) before it is sewntogether with a desired number of additional leaflets (36) to form athree-dimensional replacement valve. The flat pattern of the leaflet(36) can be used to dimension the anchoring structure shown in FIG. 10such that the commissural tabs (35) of the valve (36) will coincide withthe axial slots (21) at the distal ends (24) of the support posts (22)and the proximal edges (42) at which the leaflets will be stitched orotherwise attached to each other to form the inflow annulus of the valvecan be attached to the proximal ends (25) of the support posts (22) ofthe anchoring structure via the triangular shaped elements (31).

FIGS. 9 and 10 also show how an anchoring structure and valve may bescaled to fit different sizes of valve sinuses while retaining theproportional dimensions of the valve sinus. For example, if the width(43) of the leaflet (36) shown in FIG. 9 is chosen for a certain valvesize, then the distance (44) between support posts (22) of the anchoringstructure shown in FIG. 10 will be determined accordingly. Likewise, theheight (45) of the leaflet (36) in FIG. 9 will determine the length (46)of the support posts (22) of the anchoring structure in FIG. 10. In thismanner, a person of skill in the art can dimension both the valve andanchoring structure to fit any size of valve sinus.

Another preferred embodiment of the present invention, illustrated inFIGS. 11 and 12, comprises a valve supported by a flared anchoringstructure. The flared anchoring structure preferably comprisesflared-out sections located at both the inflow (47) and outflow rims(48) to anchor it firmly against the narrowed inflow and outflow annuliof the valve sinuses. The flared distal end (48) of the anchoringstructure is adapted to support the tab regions of the valve while theflared proximal end (47) supports the valve inflow annulus (33). Theflared-out feature prevents contact between the valve tissue and theanchoring structure if the outflow rim (48) is positioned below theupper edges of the valve leaflets (36) in the open position, while alsoallowing the anchoring structure to secure itself in a sinus cavity ofthe vascular passageway. In this embodiment, the outflow rim (48) of theanchoring structure is comprised of diamond (49) and hexagon (50) shapedstructures which facilitate collapsibility and dynamic compliance. Thecommissural tabs (35) of the valve (32) can be stitched directly to thehexagon shaped elements (50) of the outflow ring, rather than beingsecured via slots. The flared inflow rim (47) of the anchoring structurepreferably comprises a single ring in the form of an undulating orzigzag pattern to which the valve's fabric ring (37) can be sewn. Theinflow ring (47) of the anchoring structure is connected to the outflowrim (48) through vertical elements (51) that are positioned to coincidewith the commissural posts of the native sinus region. Thus, theexemplary embodiment of FIGS. 11 and 12 comprises three verticalconnecting elements (51) for a three-leaflet valve (32). However, itshould be understood that the number of vertical connecting elements(51) is meant to be adapted to the number of native commissural postspresent in the particular sinus region. The area between verticalconnector elements (51) is thus left free of any structural elements forthe accommodation of vessel openings that may be present in theparticular valve sinus.

In another preferred embodiment, as illustrated in FIG. 13, a valve issupported by an anchoring structure comprising a plurality of posts (52)with a single ring (53) at the inflow rim. The ring (53) is configuredin an undulating or zigzag pattern. In this exemplary embodiment theplurality of posts (52) number three for a three-leaflet valve sinusregion. The three posts (52) extend in the distal direction from thesingle ring (53) located at the inflow end of the anchoring structure.The proximal end (33) of the valve is attached to the ring (53) portionof the anchoring structure so that the ring (53) provides support to theinflow annulus (33) of the valve. The inflow ring (53) comprises anundulating or zigzag pattern for tire-like traction against the vesselwall. The anchoring structure portion surrounding the proximal end (33)of the valve is preferably flared in an outward direction to improveanchoring forces against the vascular wall.

The three posts (52) extend from the proximal end (33) to the distal end(34) of the valve and provide cantilevered support to the tab regions(35) of the valve at the distal end (34). The three posts (52) aredesigned to be sufficiently flexible so that they may deflect inwardlyin a controlled motion at back flow pressures to optimize the fatiguelife of the anchoring structure. The posts (52) comprise a distal end(54) for the attachment of the valve commissural tabs (35). Below thedistal end (54), the posts (52) comprise a diamond-shaped element (55)for enhanced structural stability and valve support. As with theprevious embodiments of the present invention, the design according tothe present embodiment creates open space between the proximal (33) anddistal ends of the valve (34). This also ensures that there is no directcontact between the valve and the anchoring structure and that vesselopenings located within the particular sinus remain unencumbered. Again,as in the preceding embodiments, the support posts (52) are configuredto spatially coincide with the commissural posts of the valve sinusesfor ease of positioning and anatomical optimization. [00106 Theanchoring structure embodiment illustrated in FIG. 14 comprises a valvesupported by a multi-operational anchoring structure (56). Themulti-operational anchoring structure (56) comprises a proximal end(57), a distal end (58), posts (59) extending from the proximal end (57)to the distal end (58), and a tab attachment window (60) attached toeach post (59) at the distal end (58). The tab attachment windows (60)in the present embodiment have a triangular geometry that is designed tocreate an optimal interference fit between the anchoring structure andthe commissural tabs The post (59) and tab attachment window (60)construction of the present embodiment allows inward deflection of thepost at back flow pressure, thus providing cantilevered support to thevalve and greater dynamic compliance with the sinus region. Both theproximal (57) and distal (58) ends of the anchoring structure are flaredout to better secure the valve in the valvular sinus region. Theproximal end or inflow rim (57) of the anchoring structure alsopreferably possesses barbs or hooks (61) at the proximal end (62) of thepost (59) for better attachment to the vascular wall and/or the valve'sinflow annulus. In this embodiment, the flared inflow rim (57) isdepicted as featuring two undulating rings that are substantiallyparallel to one another, while the flared outflow rim features threeundulating rings.

Yet another preferred embodiment of a valve anchoring device accordingto the present invention is illustrated in FIGS. 15-21. In thispreferred embodiment, an elliptical segment (70) anchoring structure isused to support the valve (32) as shown in FIG. 15A. As shown in FIG.15B, the elliptical segment anchoring structure (70) comprises aplurality of elliptical segments (71) that are joined together, eitherintegrally, mechanically, or by adhesive means. Each elliptical segment(71) is flared outward at the proximal (72) and distal ends (73) of theanchoring structure and curved inward at the junctures (74) with theother segments (71) assuming the shape of a potato chip. When joinedtogether side by side, the elliptical segments (71) form a tubularstructure that is flared outward at both the inflow (72) and outflow(73) ends. The junctures (74) of the elliptical segments (71) arelocated at the center of a substantially straight area of the ellipticalsegments (71) that defines the longitudinal support post elements (75)of the elliptical segment anchoring structure (70) and also provides agap location (75) near which the valve tabs (35) can be secured. The tabregions (35) extending from the seams of the valve can be attached tothe anchoring structure using any suitable means, including, sewing,stapling, wedging or adhesive means. The tab regions (35) are preferablyattached to the gaps (75) formed above the junctures (74) between theelliptical segments (71). The inflow (72) and outflow (73) rims of theanchoring structure are formed by the corresponding regions of theelliptical segments (71) that reside below and above the junctures (74).The inflow annulus of the valve can be secured at the inflow rim (72)via stitching to the inflow annulus fabric which also serves as asealing gasket.

As shown in FIG. 16A, the vertical axes (76) of the elliptical segments(71) are dimensioned to exceed the axial length (77) of the valve (32),thereby eliminating valve leaflet (36) contact with the outflow rim (73)of the anchoring structure. FIG. 16B shows how both the valve (32) andanchoring structure (70) of the present embodiment can be compressedradially to facilitate implantation. The concave configurations of theelliptical segments (71) effectively form a radial spring that iscapable of being radially collapsed under pressure for deployment andthen expanded when positioned at the implant site. One advantageousfeature of the instant design is that the region of juncture (74)between the elliptical segments (71) does not become extended uponcompression of the anchoring structure. The valve (32) and anchoringstructure (70) of the present embodiment can also be compression fitwithin a valve sinus cavity to exert radial force against the sinuswalls.

As shown in FIG. 17, the anchoring structure (70) is preferablydimensioned to be lodged substantially within a valve sinus, with theregions of juncture (74) between the elliptical segments (71) beingconfigured to reside at the location of the native commissural posts.The elliptical segment anchoring structure (70) is designed to expand atthe proximal end (72) during peak flow and at the distal end (73) duringpeak backflow pressure, thereby maintaining pressure against thevascular wall. As a result, the valve and anchoring structure (70) ofthe present embodiment will remain secure in the valve sinus withoutsutures. A metal wire frame made from a metal that exhibits a highmodulus of elasticity and that is biocompatible is preferred, such asNitinol, as such materials exhibiting superior compressibility allow theanchoring structure to be self-expandable.

A further preferred embodiment of a valve anchoring structure accordingto the present invention is illustrated in FIGS. 18A and B. In thepresent embodiment, an elliptical segment anchoring structure (70) ispresented in which the elliptical segments (71) are joined together by aspecialized double crimp (78). FIG. 18B shows that the valve tabs (35)can be secured near the double crimp (78) that joins the ellipticalsegments (71). The tab regions (35) are preferably attached to the gaps(75) between the elliptical segments (71). The inflow annulus of thevalve (33) can be secured at the inflow rim (72) via stitching to theinflow annulus fabric which also serves as a sealing gasket.

FIGS. 19A and B illustrate the double crimp (78) used to join theelliptical segments (71). As shown in FIGS. 19A and B, the double crimp(78) comprises two hollow tubes (79), one for each elliptical segment(71) to be inserted. The hollow tubes (79) of the double crimp (78) aredesigned to allow for better motion of the individual ellipticalsegments (71) and to minimize material stresses during expansion andcompression of the anchoring structure. The double crimp (78) furthercomprises a central portion (80) joining the two hollow tubes (79). Thiscentral portion (80) comprises one or more holes (81) to facilitate theattachment of the valve commissural tabs to the anchoring structure andto reduce the mass of the double crimp (78). Thus, the double crimp (78)also serves as an attachment site for the valve and further acts as astop against backflow pressure on the valve leaflets.

FIG. 20A shows the insertion of the elliptical segments (71) of thepreferred anchoring structure embodiment (70) into the double crimp(78). As with the previous embodiments, the present embodiment isdimensioned to be lodged substantially within the valve sinuses, withthe joined regions (74) of the elliptical segments in FIG. 20Bconfigured to align with the commissural posts of the sinus and theflared inflow (72) and outflow ends (73) of the anchoring structureconfigured to rest against the sinus cavities.

FIGS. 21A through G show how the elliptical segment anchoring structure(70) may additionally be covered with cloth (82), particularly at theinflow end (72) to provide traction and a gasket-like seal. Thus, thispreferred embodiment of the present invention is dimensioned to followthe sinus architecture and to lodge into the sinus cavities and againstthe inflow and outflow annuli of the sinuses for optimal securing andpositioning of the replacement valve.

FIGS. 22A and B illustrate a further preferred embodiment the presentinvention. This figure shows an elliptical segment anchoring structure(90) made from one piece of tubing. As illustrated, the support posts(91) that form the slots (92) for the valve tabs include a series ofsmall holes (93) on either side of the slot (92) to facilitate suture ormechanical attachment of the commissural tabs of the valve. Again, thisanchoring structure (90) is dimensioned to fit substantially within thevalve sinuses with the support posts (91) being configured to reside inthe commissural posts between the individual sinus cavities. The presentembodiment also exerts axial force particularly at the flared inflow(94) and outflow rims (95) against the sinus walls to anchor the valve.

Yet another embodiment of a valve and anchoring structure according tothe present invention is illustrated in FIGS. 23A through D. In thepresent embodiment, a claw anchoring structure (100) is shown in FIG.23A. This embodiment corresponds to an elliptical segment embodimentwherein the upper portions of each elliptical segment have been removed.The ends of the junctures (101) of the remaining elliptical segments areshaped into prongs or claws (102). Thus, the claw anchoring structure(100) comprises a flexible spring frame having a plurality of barbs(102), located distally just beyond where the valve leaflet tab regionsmeet the anchoring structure. The claw anchoring structure (100)preferably comprises at least one barb (102) for each valve leaflet tabincluded in the valve. The barbs (102) are designed to anchor the valve(32) and anchoring structure (100) to the vascular wall.

In another preferred embodiment of the invention, an anchoring structureis provided that lacks vertical support posts. As shown in FIG. 24, therepresentative anchoring structure configuration comprises an inflowring (110) that is adapted to being secured to the inflow annulus of thevalve (33) via stitching to the reinforced fabric sewing ring in amanner similar to the prior representative implementations. Theundulating or sinusoidal pattern of the ring (110) facilitates radialcollapse and expansion and exerts radial force against the vessel wall.The anchoring structure does not support the outflow annulus (34) of thevalve. Rather, the valve's commissural tabs (35) are attached to thesinus walls via mechanical means, such as sutures, staples, or wire.

Another representative embodiment of an anchoring structure is shown inFIG. 25A. The present embodiment comprises a dual-ring anchoringstructure (120). The dual ring (120) of the present embodiment may, asin the previous embodiment, be secured to the inflow annulus of thevalve via stitching to the reinforced fabric sewing ring. The undulatingor sinusoidal pattern of the individual rings (121) is configured suchthat the peaks (122) of one ring (121) coincide with the valleys (123)of the other ring and vice versa, thereby forming a sine-cosine pattern.This pattern facilitates radial collapse and expansion and exerts radialforce against the vessel wall. As in the previous embodiment, the dualring anchoring structure (120) does not support the outflow annulus ofthe valve. Rather, the valve's commissural tabs are attached to thenative sinus walls via mechanical means, such as sutures, staples, orwire, or additionally by the adhesive means disclosed herein.

FIG. 25B shows another dual ring embodiment of the present invention.This anchoring structure is comprised of an upper (distal) dual ring(130) and a lower (proximal) dual ring (131). The lower dual ring (131)is connected to the proximal end of the valve at the inflow annuluswhile the upper dual ring (130) is connected to the distal end of thevalve at the outflow annulus. The valve may be connected to the rings(130, 131) via sutures, clips or any other suitable means forattachment. The valve and the attached proximal (131) and distal (130)rings can be collapsed and inserted via a catheter. Once the valve hasreached its desired location in the vascular passageway, the two rings(130, 131) are expanded to secure the valve in the vascular passageway.As in the previous embodiment, each dual ring (130, 131) comprises awire frame with a circular cross-section and a sinusoidal pattern. Thesinusoidal pattern may be of a sine-cosine shape with a varied frequencyand amplitude. One or more longitudinal rods (132) may be used toconnect the two dual rings (130, 131) and maintain longitudinalseparation and radial orientation. The rods (132) may be removable sothat once the valve is implanted in the vascular passageway they can beremoved.

In another preferred embodiment, illustrated in FIG. 26, an upper singlering (140) with an undulating or zigzag pattern provides support to thetab regions (35) of the valve (32) at the distal end (34) of the valvewhereas a lower single ring (141) configured in an undulating orsinusoidal pattern provides support to the inflow annulus (33) at theproximal end of the valve (32). The inflow ring (141) is stitched to thesewing fabric wrapped around the circumference of the inflow annulus ofthe valve, as described previously. The outflow ring (140) of theanchoring structure generally resides above the leaflets (36) to avoidleaflet contact. To improve traction, the inflow or outflow rings maycomprise attachment barbs (142). The structural dissociation between therings (140, 141) provides improved dynamic compliance while retainingthe benefits of a two ring design.

Yet another embodiment of a valve and anchoring structure according tothe present invention is illustrated in FIGS. 27A through C. In thevalve anchoring structure according to the present embodiment shown inFIGS. 27A and C, the valve (32) is supported by a tubular anchoringstructure (150). The tubular anchoring structure (150) is preferablymade of metal or plastic. The tubular anchoring structure (150) is alsopreferably designed to be expandable. For example, the anchoringstructure may be designed to be self-expandable, balloon-expandable, ormechanically-expandable. The tab regions (35) of the valve (32) arepreferably attached to the distal end (151) of the tubular anchoringstructure (150) using staples, sutures, wire fasteners, or any othersuitable means. The inflow rim (152) of the tubular anchoring structuremay comprise a plurality of suture bores (153) to facilitate attachmentof the valve (32). The tubular anchoring structure (150) also comprisesvertical support posts (154) with axial slots (155) for the insertion ofthe valve tabs (35). The vertical support posts (154) extend to thedistal end (151) of the tubular anchoring structure (150). In apreferred implementation of the of the present embodiment, the means ofattachment, or an alternative means, is used to also attach the tabregions (35) of the valve (32) to the vascular wall thereby securing thevalve (32) and tubular anchoring structure (150) in the valve sinuses.Such fastening means can also be optionally used at the inflow annulusto provide additional anchoring.

Another embodiment of a valve and anchoring structure according to thepresent invention is illustrated in FIG. 28. In the present embodiment,a dual-ring anchoring structure (160) is shown, as seen in FIGS. 28C andD, with an inflow ring (161) and an outflow ring (162) connected by avertical element (163) comprised of two posts (164). The anchoringstructure (160) is designed to be circumferentially collapsible as canbe seen in FIGS. 28A and B. As shown in FIGS. 28C and D, the anchoringstructure (160) is collapsed by sliding the two posts (164) that areadjacent to each other in the expanded state (FIG. 28D) past each otherto decrease the circumference of the upper outflow (162) and lowerinflow (161) rings (FIG. 28C). Thus, prior to implantation the anchoringstructure (160) is collapsed and, once the valve is properly positionedin the valve sinuses, the anchoring structure freely self-expands to itsoriginal dimensions. The self-expanding behavior of the presentembodiment is due to Nitinol's relatively high modulus of elasticity,which imparts superior spring-like properties to the anchoringstructure. Alternatively, if the anchoring structure is constructed of anon-self expanding material, it may be mechanically collapsed andexpanded using the devices disclosed herein.

Another embodiment of a valve and anchoring structure according to thepresent invention is illustrated in FIGS. 29A and B. In the presentembodiment, a dual-ring anchoring structure (170) is shown, with aninflow ring (171) and an outflow ring (172) connected by a verticalelement (173) comprised of two posts (174). The inflow rim may furthercomprise tissue mounting posts (175). The anchoring structure (170) isdesigned to be circumferentially collapsible. FIG. 29A shows how theposts (174) are separated in the expanded state and FIG. 29B shows howthe posts (174) form a single vertical element (173) in the collapsedstate. Thus, prior to implantation the anchoring structure is collapsedand upon the positioning of the valve assembly in the valve sinuses, theanchoring structure (170) freely self-expands to its originaldimensions. As in the previous embodiment, the self-expanding behaviorof the present embodiment is a function of Nitinol's high modulus ofelasticity. Alternatively, if the anchoring structure is constructed ofa non-self expanding material, it may be mechanically collapsed andexpanded using the devices disclosed herein.

A further embodiment of a valve and anchoring structure according to thepresent invention is illustrated in FIGS. 30A and B. The presentembodiment comprises a spring-aided anchoring structure (180). Thespring aided anchoring structure (180) preferably comprises threemembers (181) that are radially collapsible for implantation into thevalve sinuses. The members (181) comprise peaks (182) that serve asvalve attachment points and valleys (183) that serve to lodge theanchoring structure at the valve sinus inflow annulus. Followingimplantation, the anchoring structure (180) is expanded to its originaldimensions by coil springs (184) that provide an outward radial force oneach member. In a preferred embodiment, shown in FIG. 30B, the springaided anchoring structure (180) comprises at least one anchoring section(185) for selectively securing the anchoring structure (180) in thevalve sinus at the inflow annulus. Although the present embodimentillustrates three members (181) and three coil springs (184), it shouldbe appreciated that two or more members (181) with a correspondingnumber of coil springs (184) may be used.

The anchoring structures of the present invention may be constructedfrom superelastic memory metal alloys, such as Nitinol, described inU.S. Pat. No. 6,451,025, incorporated herein by reference. Nitinolbelongs to a family of intermetallic materials which contain a nearlyequal mixture of nickel and titanium. Other elements can be added toadjust or modify the material properties. Nitinol exhibits both shapememory and superelastic properties. The shape memory effect of Nitinolallows for the restoration of the original shape of a plasticallydeformed structure by heating it. This is a result of the crystallinephase change known as thermoelastic martensitic transformation. Thus,below the transformation temperature, Nitinol is martensitic, i.e.easily deformable. Heating the material converts the material to itshigh strength, austenitic condition. Accordingly, prior to implantation,the valve assembly is chilled in sterile ice water. Upon cooling, theNitinol anchoring structure enters its martensite phase. Once in thisphase, the structure is malleable and can maintain a plasticallydeformed crushed configuration. When the crushed anchoring structurecomprising the valve is delivered into the valve sinus, the increase intemperature results in a phase change from martensite to austenite.Through the phase change, the anchoring structure returns to itsmemorized shape, and thus expands back to its original size.

The anchoring structures can also be designed to use the superelasticityproperties of Nitinol. With the superelastic design, the chillingprocedure would not be necessary. The anchoring structure would becrushed at room temperature. The phase change to martensite would beaccomplished by means of the stress generated during the crushingprocess. The anchoring structure would be held in the crushedconfiguration using force. Force is removed once the anchoring structureis delivered to the valve sinus, resulting in a phase transformation ofthe Nitinol from martensite to austenite. Through the phase change, theanchoring structure returns to its memorized shape and stresses andstrains generated during the crushing process are removed.Alternatively, the anchoring structures of the present invention may becomposed of a non-self expanding suitable material, such asbiocompatible metals, including titanium, and plastics. Whether thevalve assembly is designed to be self-expandable or non-self expandable,it may be compressed (and expanded, if non-self expandable) forimplantation using the expansion and contraction devices disclosedherein.

Expansion and Contraction Devices

A preferred embodiment of an expansion and contraction device forimplanting the valve assemblies of the present invention is illustratedin FIGS. 31-33. As seen in FIGS. 31A and B, the device of the presentembodiment comprises a group of bendable hollow tubes or wires (200), agrip handle (201), and a circular element (202) that holds the wires(200) together at their proximal ends (203). Each wire (200) comprises aproximal end (203), a distal end (204) and a hollow shaft (205) runningfrom the proximal end (203) to the distal end (204). The wires (200) areattached to the grip handle (201) at their proximal ends (203) via thecircular element (202) such that the wires form a circular pattern.

As shown in FIGS. 32A and B, the expansion and contraction devicefurther comprises a cylinder (206) having a proximal end (207) and adistal end (208). The cylinder (206) has holes (209) drilled along itsdistal perimeter (208). The holes (209) in the cylinder (206) arepreferably drilled at an outward angle so that by forcing the wires(200) through the angled holes (209), the distal ends (204) of the wires(200) are driven radially outward. As the wires (200) are pushed furtherthrough the outwardly angled cylinder holes (209), the further the wires(200) spread radially, thereby expanding the anchoring structure that ispositioned over the wires (200). Accordingly, the angle of the cylinderholes (209) controls the relationship between the longitudinal movementof the wires (200) and their radial dilation.

As shown in FIG. 33, a representative anchoring structure (210) of thepresent invention is attached to the distal ends (204) of the hollowwires (200). The cylinder (206) having a proximal end (207) and a distalend (208) has holes (209) drilled along its distal perimeter (208). Theholes (209) in the cylinder (206) are drilled at an outward angle sothat by forcing the wires (200) through the angled holes (209), thedistal ends (204) of the wires (200) are driven radially outward. Asthis figure shows, when the wires (200) are pushed further through theoutwardly angled cylinder holes (209), they are forced to spreadradially, thereby expanding the anchoring structure (210) that ispositioned over the wires (200) at their distal ends (204). In apreferred embodiment, a long suture is routed from the proximal end tothe distal end of the wire down its hollow shaft, looped around asegment of the anchoring structure at the distal end of the wire andthen routed back to the proximal end of the wire, where it is secured.Attached to the distal ends (204) of the hollow wires, the anchoringstructure (210) contracts and expands radially in response to thelongitudinal motion of the wires (200). Pulling the grip handle (201)proximally contracts the anchoring structure (210) into a collapsedstate for implantation whereas pushing the grip handle (201) distallyexpands the anchoring structure (210). When the anchoring structure(210) is positioned in a desirable location in the vessel and expandedto the desired dimensions, the sutures are severed and removed from theproximal end (203) of the wires (200) in order to disconnect theanchoring structure (210) from the device. The device of the presentembodiment is removed, thereby leaving the valve assembly securelysituated in the valve sinus.

Another expansion and contraction device is illustrated in FIGS. 34 and35. As shown in FIG. 34, the device of the present embodiment comprisesa tube (220), multiple wall panels (221), springs (222) corresponding tothe multiple wall panels (221), a spindle (223) and a plurality ofconnecting wires (224). The tube (220) comprises a hollow shaft (225)having a radial center (226), a proximal end (227), a distal end (228)as shown in FIG. 35, an interior wall (229) and an exterior wall (230),wherein a hole (231) corresponding to each wall panel (221) extendsthrough the interior (229) and exterior wall (230) of the tube (220). Ina preferred embodiment, the perimeter of the exterior wall (230) issurrounded by adjacent wall panels (221), only buffered by the springs(222) corresponding to the wall panels (221). The spindle (223) isattached to the interior wall (229) of the tube (220), preferably facingthe tube's (220) radial center (226). A connecting wire (224) isattached to each wall panel (221) and routed through the spring (222)and the corresponding hole (231) in the tube wall (229, 230) to meet theother connecting wires (224), preferably at the radial center (226) ofthe tube (220).

As shown in FIG. 35, upon meeting at the radial center (226) of the tube(220), the wires (224) having been wrapped around the spindle (223), nowrun parallel to the tube's (220) longitudinal axis. By pulling the wires(224) proximally, the attached panels (221) compress the springs (222)against the tube's (220) exterior wall (230). In this compressed state,a collapsed valve assembly of the present invention can be placed overthe panels (221). Once the device of the present embodiment, loaded withthe valve assembly, is positioned at the desired location in the valvesinus, the tension in the wires (224) is relieved to force the wallpanels (221) outward, thereby expanding the anchoring structure andvalve. The length of the uncompressed spring (222) determines thediameter to which the anchoring structure can be expanded. The anchoringstructure can optionally be secured to the wall panels (221), bystaples, sutures, wire fasteners, or any other suitable means, so thatthe valve assembly may be selectively expanded and collapsed bypreferably varying the tension on the connecting wires.

In FIGS. 36A and B, another preferred embodiment of an expansion andcontraction device of the present invention is presented. In thisembodiment, the anchoring structure (240) is composed of a shape memorymetal or the like having a relatively high modulus of elasticity, andpossessing an outward spring-like force when in a compressed state.Therefore, spring loaded wall panels are not necessary in the presentembodiment. Instead, the wires (241) pass through sutures (242) that arethreaded through holes (243) in the tube (244) wall and wrap aroundportions of the anchoring structure. Thus, the wires (241) keep theanchoring structure (240) compressed by pulling the sutures (242) aroundthe anchoring structure (240) against the tube (244). Alternatively, thetube structure can be omitted with only the wires (241) and sutures(242) keeping the anchoring structure (240) in a compressed state. Thiswould ensure that the valve within the anchoring structure is notcontacted by any mechanical elements, such as a tube (244).Alternatively, the tube could be made from a cloth- or tissue-likematerial. Once the anchoring structure (240) is positioned in thedesired location in the valve sinus, the wires (241) can be retracted,allowing the anchoring structure (240) to self-expand such that the tube(244) can be withdrawn, leaving the anchoring structure (240) securelylodged at the desired location of implantation. The sutures (242), whichwill remain wrapped about the anchoring structure (240), can be made ofbiodegradable material and thus will be resorbed by the body within amatter of days.

The contraction and expansion device illustrated in FIGS. 37 and 38represents another preferred embodiment of the present invention. Asillustrated in FIG. 37, each wall panel (250) is connected to a pin(251) which runs through the corresponding hole (252) in the tube (253)wall. The pin (251), protruding radially inward from the tube'sinterior, is preferably spring-loaded (254) toward the radial center ofthe tube (253). In a zero energy state, the wall panels (250) restagainst the exterior wall of the tube (253) and the collapsed anchoringstructure rests against the wall panels (250). Instead of wires, thepresent embodiment comprises a longitudinal shaft (255) running throughthe radial center of the tube. The shaft is comprised of a proximal end(256) and a distal end (257). The distal end (257) is connected to acentral plate (258) having spiral shaped edges (259) as shown in FIGS.37B and C. The central plate (258) is located in the tube (253),parallel to the tube's cross-section and is aligned with thespring-loaded (254) pins (251). The plate's spiral-shaped edges (259)preferably cause the distance from the plate's perimeter to the tube'sradial center to vary along the plate's (258) perimeter. When the shaft(255) is rotated, the edge of the plate (259) pushes against each pin(251), thereby driving the corresponding panels (250) outward andexpanding the anchoring structure, as FIG. 37C shows.

FIGS. 38A and B show how rotation of the shaft (255) pushes the wallpanels (250) radially out, thereby expanding the anchoring structure(260). In a preferred embodiment, the anchoring structure (260) issutured to the wall panels (250) to allow expansion and contraction ofthe anchoring structure by alternating rotation of the shaft. Thesutures are preferably removable from the shaft's (255) proximal end tofree the valve assembly from the device following implantation in thevalve sinus.

In still another embodiment, as illustrated in FIG. 39, an expansion andcontraction device similar to the previous embodiment is presented.Instead of a device comprising a central plate with spiral-shaped edgesof varying dimensions, the present preferred embodiment utilizes acircular disk (270) with pre-cut spiral-shaped grooves (271)corresponding to the spring-loaded pins (272). Preferably, the grooves(271) provide a track of varying depth for the pins (272) such that thepins (272) are forced radially outward upon rotation of the disk (270),thereby expanding the anchoring structure.

Adhesive Means for Securing Replacement Valves

In addition to the disclosed features and mechanisms for securing thevalve assembly comprising a valve and anchoring structure into position,the present invention provides the use of biocompatible adhesives. Anumber of adhesives may be used to seal the valve assembly to thesurrounding tissue in the valve sinus. The following are examples ofavailable adhesives and methods of use:

U.S. Pat. No. 5,549,904, the entire contents of which are incorporatedherein by reference, discloses a formulated biological adhesivecomposition comprising tissue transglutaminase and a pharmaceuticallyacceptable carrier, the tissue transglutaminase in an effective amountto promote adhesion upon treatment of tissue in the presence of adivalent metal ion, such as calcium or strontium. In operation, the twocomponents are mixed to activate the sealable fixation means forsecurely fixing the valve assembly to tissue at a desired valvelocation.

U.S. Pat. No. 5,407,671, the entire contents of which are incorporatedherein by reference, discloses a one-component tissue adhesivecontaining, in aqueous solution, fibrinogen, F XIII, a thrombininhibitor, prothrombin factors, calcium ions and, where appropriate, aplasmin inhibitor. This adhesive can be reconstituted from afreeze-dried form with water. It can contain all active substances inpasteurized form and is then free of the risk of transmission ofhepatitis and HTLV III. In operations, the one-component tissue adhesiveis reconstituted from a freeze-dried form with water to activate thesealable fixation means for securely fixing the valve assembly to tissueat a desired valve location.

U.S. Pat. No. 5,739,288, the entire contents of which are incorporatedherein by reference, discloses a method for utilizing a fibrin sealantwhich comprises: (a) contacting a desired site with a compositioncomprising fibrin monomer or noncrosslinked fibrin; and (b) convertingthe fibrin monomer or noncrosslinked fibrin to a fibrin polymerconcurrently with the contacting step, thereby forming a fibrin clot. Inoperation, the fibrin monomer or noncrosslinked fibrin is converted toactivate the sealable fixation means for securely fixing the valveassembly to tissue at a desired valve location.

U.S. Pat. No. 5,744,545, the entire contents of which are incorporatedherein by reference, discloses a method for effecting the nonsurgicalattachment of a first surface to a second surface, comprising the stepsof: (a) providing collagen and a multifunctionally activated synthetichydrophilic polymer; (b) mixing the collagen and synthetic polymer toinitiate crosslinking between the collagen and the synthetic polymer;(c) applying the mixture of collagen and synthetic polymer to a firstsurface before substantial crosslinking has occurred between thecollagen and the synthetic polymer; and (d) contacting the first surfacewith the second surface to effect adhesion between the two surfaces.Each surface can be a native tissue or implant surface. In operation,collagen and a multifunctionally activated synthetic hydrophilic polymerare mixed to activate the sealable fixation means for securely fixingthe valve assembly to tissue at a desired valve location.

U.S. Pat. No. 6,113,948, the entire contents of which are incorporatedherein by reference, discloses soluble microparticles comprisingfibrinogen or thrombin, in free-flowing form. These microparticles canbe mixed to give a dry powder, to be used as a fibrin sealant that isactivated only at a tissue site upon dissolving the solublemicroparticles. In operation, soluble microparticles comprisingfibrinogen or thrombin are contacted with water to activate the sealablefixation means for securely fixing the valve assembly to tissue at adesired valve location.

U.S. Pat. Nos. 6,565,549, 5,387,450, 5,156,911 and 5,648,167, the entirecontents of which are incorporated herein by reference, disclose athermally activatable adhesive. A “thermally activatable” adhesive is anadhesive which exhibits an increase in “tack” or adhesion after beingwarmed to a temperature at or above the activation temperature of theadhesive. Preferably, the activation temperature of the thermallyactivatable adhesive is between about 28° C. and 60° C. More preferably,the activation temperature is between about 30° C. and 40° C. Oneexemplary thermally activatable adhesive is described as Example 1 inU.S. Pat. No. 5,648,167, which is incorporated by reference herein. Itconsists of a mixture of stearyl methacrylate (65.8 g), 2-ethylhexylacrylate (28.2 g) and acrylic acid (6 g) monomers and a solution ofcatalyst BCEPC (0.2 g) in ethyl acetate (100 g) is slowly added by meansof dropper funnels to ethyl acetate (50 g) heated under reflux (80degrees C.) in a resin flask over a period of approximately 6 hours.Further ethyl acetate (50 g) is added to the mixture during thepolymerization to maintain the mixture in a viscous but ungelled state.In operation, thermally activatable adhesive is heated to activate thesealable fixation means for securely fixing the valve assembly to tissueat a desired valve location.

FIG. 40 shows a preferred embodiment, wherein an outer circumferentialreservoir (401) is located at an outermost radius of a valve anchoringstructure (400) when the anchoring structure (400) is in an expandedstate, wherein the reservoir is filled with a sealable fixation meansfor securely fixing the valve assembly (400) at a desired locationwithin a body cavity. FIG. 40 further illustrates one embodiment of thereservoir (401) comprising a sealable fixation means, wherein thesealable fixation means may comprise a one-component biologicaladhesive. The sealable fixation means may be activated by exposing thebiological adhesive to blood or heat.

FIG. 41 illustrates another preferred embodiment wherein the sealablefixation means may comprise a two-component biological adhesive. Thesealable fixation means may be activated by mixing the two components.Thus, for example, if one reservoir (402) contains microparticles thatare activated by contact with water, the second reservoir (403) wouldcontain the water for the activation of the microparticles. This figurealso shows that the reservoirs may be arranged concentrically as shownin FIG. 41B or adjacent to each other as shown in FIG. 41A.

FIG. 42 illustrates an exemplary reservoir (401) which may be attachedto the valve anchoring structure by its inner wall (404) by sutures,glue, staples or some other appropriate method. FIG. 42 furtherillustrates a thin spot (405) on the outer wall (406) of the reservoir(401). The thin spots (405) are areas on the reservoir (401) that areadapted to rupture when placed under certain levels of pressure. Thepressure is exerted on the thin spots (405) as the reservoir (401) isexpanded along with the valve anchoring structure. The thin spots (405)are unable to withstand the pressure and therefore rupture releasing thecontents of the reservoir (401) or reservoirs. In a preferredembodiment, the reservoir (401) is made of an elastic material thatexpands along with the expansion of the valve anchoring structure.

FIG. 43 illustrates a cross sectional view of the reservoir (401). Thereservoir (401) may contain a lumen (407) which extends along at least aportion of the circumference of the reservoir. The reservoir (401) hasone or more thin spots (405) along its outermost circumference, whereinthe thin spots (405) are sized and configured to rupture when thereservoir (401) is expanded to an appropriate diameter. When theanchoring structure comprising the valve is fully expanded, the pressureexerted upon the expanded thin spots (405) causes them to rupture. Instill another preferred embodiment, the reservoir (401) is made of abiodegradable material adapted for erosion or rupture to release thecontent of the reservoir (401) and activate the sealable fixation meansin a desired timeframe after implantation. In a further preferredembodiment, a circumferentially outermost portion is pressure sensitiveto rupture, wherein the contents of the reservoir (401) are releasedwhen the reservoir (401) is compressed against the sinus cavities duringexpansion and implantation of the valve assembly.

FIG. 44 shows a cross-sectional view of another preferred embodiment,illustrating thin spots (405) on a reservoir having two concentriccomponent compartments, an inner compartment (408) and an outercompartment (409). Component A in an inner compartment (408) andcomponent B in an outer compartment (409) are to be mixed to formadhesive for sealing the valve assembly against the valve sinuses. Theinner compartment (408) has a plurality of thin spots (405) along itsoutermost circumference, wherein the thin spots (405) are sized andconfigured to rupture when the reservoir (401) is expanded to anappropriate diameter. The outer compartment (409) also has a pluralityof thin spots (405) along its innermost circumference. The thin spots(405) of the inner compartment (408) and the thin spots (405) of theouter compartment (409) may be located adjacent to each other. In onepreferred embodiment, the space between the adjacent pair of thin spots(405) on the inner (408) and outer (409) compartment may comprise apiercing element that is activated to rupture the thin spot or the pairof adjacent spots when the reservoir is expanded to an appropriatediameter or a predetermined diameter. Other embodiments of reservoirconfiguration, for example, two parallel compartments circumferentiallyor longitudinally, and suitable activation mechanism for the sealablefixation means are also within the scope of the present invention.

The present invention further comprises methods and devices for thesizing of native valves that require replacement.

Methods and Apparatus for Valve Sizing

Intravascular ultrasound (IVUS) uses high-frequency sound waves that aresent with a device called a transducer. The transducer is attached tothe end of a catheter, which is threaded through a vein, artery, orother vessel lumen. The sound waves bounce off of the walls of thevessel and return to the transducer as echoes. The echoes can beconverted into distances by computer. A preferred minimally invasivevalve replacement sizer is shown in FIGS. 45A and B. For purposes ofthis application, the distal end or portion refers to the area closer tothe body while the proximal end or portion refers to the area closer tothe user of the valve replacement sizer. The device comprises aguidewire (500), an intravascular ultrasound (IVUS) catheter (501)having a transducer (502), and a balloon dilatation catheter (503) allpositioned within the central lumen of a catheter. The transducer (502)is positioned in the IVUS sizing window (504) of the balloon catheter.The guide wire (500) advances and guides the catheter (501) to theappropriate location for valve sizing. FIG. 45A shows the catheter indeflated form, whereas in FIG. 45B the balloon dilatation catheter (503)has inflated the balloon (505).

In a preferred embodiment, shown in FIG. 46, the catheter (510) containsmultiple lumens (511) in order to house a guidewire (512), an IVUScatheter (513), and a balloon dilatation catheter (514). FIG. 46illustrates a cross sectional view. One of the separate lumens (511)contains the guidewire (512), another contains the IVUS catheter (513),and another contains the balloon dilatation catheter (514). The balloondilatation catheter (514) has a balloon (515) attached circumferentiallysurrounding the balloon dilatation catheter (514) as well as a portionof the catheter (510).

FIG. 47 shows a balloon dilatation catheter (516) comprising a balloon(517) that circumferentially surrounds a portion of the catheter (518)proximal to its distal portion (519). More specifically, the balloon(517) comprises an outer wall (520) that circumferentially surrounds aportion of the catheter (518) near its distal portion (519). The balloon(517) also has a distal end (521) and a proximal end (522). In apreferred embodiment, within the area encompassed by the balloon, atransducer (523) is located on the IVUS catheter (524). Directly overthe transducer (523) a sizing window (525) is placed on the IVUScatheter (524) to enable signals to be transmitted and received by thetransducer (523) without interference. In a preferred embodiment, thesizing window (525) is simply an empty space. However, the sizing window(525) could be made from any substance which does not interfere with thesignals emitted and received by the transducer (523).

Preferably, the balloon (517) is round but other shapes are possible andcontemplated for use with the valve sizing apparatus. In particular,FIG. 48 shows a cross section of an inflated balloon (530) with curvesforming leaflets (531) to enable fluid (532) to pass through the vesselwhile the balloon (530) is in its inflated state and the outer edges(533) of the leaflets (531) are in contact with the vessel wall (534) tomeasure the diameter. The balloon may further be made from compliant ornon-compliant material.

FIG. 49 shows a preferred embodiment wherein the balloon (540) isinflated with saline (541). Preferably, the saline is pumped into theballoon (540) through the balloon dilatation catheter. Alternatively,the balloon (540) may be inflated with a gas or any other suitablesubstance. The balloon (540) is inflated to a chosen pressure by theperson using the valve replacement sizer. When the balloon (540) hasbeen inflated, the outermost portion of the outer wall (542) will be incontact with the vessel wall (543) or other lumen at the location wherethe replacement valve is to be placed. When the balloon (540) iscompletely inflated, the farthest radial points of the balloon's outerwall (542) will be equidistant to the center of the catheter (544). Thisdistance is labeled as R. The transducer (545) may or may not be at thecentermost point of the inflated balloon (540). Any deviation from thecentermost point by the transducer (545) may be accounted for whencalculating the diameter of the vessel lumen. However, the signalemitted by the transducer (545) preferably intersects the balloon (540)at its greatest radius.

FIG. 50 shows a preferred embodiment, wherein a transducer (550) emitsan ultrasonic signal (556) in a perpendicular direction to the IVUScatheter (551). The signal is then reflected off the outer wall (552) ofthe balloon (540) and received by the transducer (550). The transducer(550) then transmits the data to the auxiliary processor (553) todetermine the radius and diameter of the vessel lumen. Alternatively, aninfrared light may be emitted and received by the transducer (550) todetermine the radius and diameter of the vessel lumen. The diameter iscalculated by knowing the speed of the signal and the time it takes forthe signal to be reflected off the balloon wall (552) back to thetransducer (550). The known speed is multiplied by the time to determinethe radius of the balloon (540). The radius may be adjusted if thetransducer (550) was not located at the centermost point of thecatheter.

The present invention further provides devices and methods to remove thenative diseased valves prior to implantation of the replacement valveassembly. In one embodiment of the present invention, the valve removingmeans is provided by the replacement valve assembly. In anotherembodiment, the valve removing means is provided by a valve sizingdevice of the present invention.

Valve Assemblies With Native Valve Removing Capabiliy

The present invention further provides valve assemblies comprisingnative valve removing capabilities. Thus, in a preferred embodiment, avalve anchoring structure having cutting means located at the annulusbase for cutting a native valve is provided. Accordingly, when passingthe valve assembly comprising the valve and anchoring structure throughthe vessel with the anchoring structure in a collapsed state, thecutting means can be advanced against the native valve with theanchoring structure in a partially expanded state. In this manner, theanchoring structure comprising the cutting means cuts at least a portionof the native valve by deploying the cutting means, before the valveassembly is secured to the desired valve location with the anchoringstructure in the expanded state.

It is one object of the present invention to provide a valve assembly ofthe preferred embodiment having a tissue valve and an anchoringstructure, which permits implantation without surgery or with minimalsurgical intervention and provides native valve removing means forremoving a dysfunctional native valve, followed by valve replacement.The native valve removing means on the anchoring structure is selectedfrom a group consisting of: a plurality of sharp edge elements, eachsharp edge element having a sharp end enabling the element to cutthrough at least a portion of the native valve; a plurality of electrodeelements, wherein radiofrequency energy is delivered to each electrodeelement enabling the electrode element to cut through at least a portionof the native valve, and a plurality of ultrasound transducer elements,wherein ultrasound energy is delivered to each transducer elementenabling the transducer element to cut through at least a portion of thenative valve.

Percutaneous implantation of a valve prosthesis is achieved according tothe invention, which is characterized in that the valve anchoringstructure is made from a radially collapsible and re-expandablecylindrical support means for folding and expanding together with thecollapsible replacement valve for implantation in the body by means ofcatheterization or other minimally invasive procedure. Catheters andcatheter balloon systems are well known to those of skill in the art,for example, U.S. Pat. No. 6,605,056 issued on Aug. 23, 2003.

Accordingly, in one preferred embodiment of the invention shown in FIG.51, the anchoring structure (600) comprises at least one ultrasoundtransducer (601) at the distal end portion of the lower ring (602),wherein each ultrasound transducer is sized and configured withultrasound energy as cutting means for cutting a native valve.Ultrasound energy is delivered through conductor means (603) to eachtransducer element (601) enabling the transducer element (601) to cutthrough at least a portion of the native valve. In one embodiment, theconductor (603) passes through a delivery means and is connected to anexternal ultrasound energy generator. The ablative ultrasound deliverymeans and methods are well known to one skilled in the art, for example,U.S. Pat. No. 6,241,692 issued on Jun. 5, 2001.

FIG. 52 shows another preferred embodiment of a native valve removalsystem comprising a valve assembly having radiofrequency cutting means.In this preferred embodiment, the anchoring structure comprises at leastone radiofrequency electrode (610) at the distal end portion of thelower ring (602), wherein each radiofrequency electrode (610) is sizedand configured with radiofrequency energy as cutting means for cutting anative valve. Radiofrequency energy is delivered through conductor means(611) to each electrode element (610) enabling the electrode element tocut through at least a portion of the native valve. In one embodiment,the conductor (611) passes through delivery means and is connected to anexternal radiofrequency energy generator. The ablative radiofrequencydelivery means and methods are well known to one skilled in the art, forexample, U.S. Pat. No. 6,033,402 issued on Mar. 7, 2000.

FIG. 53 shows another embodiment of an anchoring structure having sharpedge cutting means (620). In one preferred embodiment, the anchoringstructure comprises a set of sharp edge cutting elements (621) at thedistal end portion of the cutting means (620) of the lower ring (602) ofthe anchoring structure, wherein each cutting element (621) has acutting tip (622), and wherein each cutting element (621) of the cuttingmeans is sized and configured, optionally with radiofrequency energy, ascutting means for cutting a native valve. In one embodiment, sharp edgecutting means on the delivery apparatus is rotatable, enabling thecutting element (621) to cut through at least a portion of the nativevalve. Sharp edge cutting means, with optionally ablative radiofrequencydelivery means and methods, are well known to one skilled in the art,for example, U.S. Pat. No. 5,980,515 issued on Nov. 9, 1999.

FIG. 54 shows a partially inflated balloon catheter. A balloon catheter(630) is introduced in the vessel. The balloon means (632) of theballoon catheter (630) is led out of the protection cap (633) at thecatheter tip (634) and is partly inflated through a fluid channel (635),which is led to the surface of the patient. In one embodiment, theballoon (632) is partially expanded and the sharp end (636) of thecutting means of the valve anchoring structure (637) is advanced to cutand remove at least a portion of the native valve. In anotherembodiment, the valve anchoring structure (637) comprises an ultrasoundor radiofrequency cutting means (638). In one embodiment, the supportstructure is expanded at about 30 to 95% of full expansion for cuttingthe native valve. More preferably, the support structure is expanded atabout 50 to 90% of the full expansion. In another embodiment, theballoon catheter (630) comprises a central channel (639) with respect toa central axial line (640) to receive a guide wire (641) which is usedin a way known for viewing the introduction of the catheter throughfluoroscopy.

Some aspects of the present invention provide a method of endovascularlyimplanting a valve through a vessel, comprising the steps of providing acollapsibly expandable valve assembly that comprises an anchoringstructure according to the present invention with an annulus base and acollapsible valve connected to the anchoring structure, the collapsiblevalve being configured to permit blood flow in a direction and preventblood flow in an opposite direction, the anchoring structure havingcutting means located at the annulus base for cutting a native valve,passing the valve assembly through the vessel with the anchoringstructure in a collapsed state, advancing the cutting means against thenative valve with the anchoring structure in a partially expanded state,cutting at least a portion of the native valve by deploying the cuttingmeans, and securing the valve assembly to the desired valve locationwith the anchoring structure in the expanded shape.

In operations, a method of implanting a valve assembly according to thepresent invention is given below: a valve assembly made of an anchoringstructure of the present invention and a collapsible valve, as describedabove, is placed on a deflated balloon means and is compressed thereon,either manually or by use of the expansion/compression devices of theinstant invention; the balloon means and the valve assembly are drawninto an insertion cover; a guide wire is inserted into a vessel throughthe central opening of the balloon catheter under continuousfluoroscopy; the insertion cover conveys the guide wire to a point inthe channel in the immediate vicinity of the desired position of thevalve assembly; the balloon means is pushed out of the protection capand the valve assembly is positioned in the desired position ifnecessary by use of further imaging means to ensure accuratepositioning; the balloon means is inflated partially; the valve assemblyis advanced with its cutting means cutting at least a portion of thenative valve; the balloon means is further inflated to position thevalve at a desired site, preferably against the truncated valvularannulus; the balloon means is deflated; and the balloon means withentrapped tissue and debris inside the filter means, the guide wire, andthe protection cap are drawn out and the opening in the channel, if any,wherein the valve prosthesis is inserted can be closed.

The present invention also provides for devices and methods to preventthe release of debris during removal of the native diseased valves fromtraveling to distant sites where such debris may cause undesirablephysiological effects.

Distal Protection Assembly

As described above, removal or manipulation of diseased valves mayresult in dislodgment of parts of the valve or deposits formed thereonwhich may be carried by the fluid to other parts of the body. Thus, thepresent invention provides for specialized filters that capture materialand debris generated during valve replacement procedures. The distalprotection devices of the present invention are also effective intrapping material that may be released during other percutaneousinterventional procedures, such as balloon angioplasty or stentingprocedures by providing a temporary valve and filter in the same device.

In one preferred embodiment, shown in FIGS. 55A and B, the presentinvention provides for a temporary valve (700), which may be deployed ata desired location in a collapsed state and then expanded and secured tothe walls of the passageway. The temporary valve (700) comprises twoconcentric one-way valves, an outer valve (701) and an inner valve (702)disposed within the outer valve (701), that open in opposite directionsas shown in FIG. 55B. The outer valve (701) opens in response topositive fluid flow pressure, thereby regulating blood flow insubstantially one direction. The inner valve (702) opens in the oppositedirection of the outer valve (701) to facilitate the insertion ofcatheter based equipment (703) as shown in FIG. 55C and functions as aseal through which such equipment may be passed. The pressure requiredto open the individual valves may be manipulated to facilitate positivefluid flow, while precluding or minimizing retrograde flow that mightotherwise occur as a result of back flow pressure. Hence, it iscontemplated that the inner valve (702) be configured or constructed toopen with relatively more pressure than that required to open the outervalve.

The outer (701) and inner valves (702) of the temporary valve (700) maybe coupled together by radial support members. In one embodiment, theradial support members couple the inner surface of the outer valve tothe outer surface of the inner valve. The length of the radial supportmeans depends upon the dimension of the blood vessel or body cavitywithin which the temporary valve is to be deployed.

The temporary valve may be constructed from material that is capable ofself-expanding the temporary valve, once it is deployed from thecollapsed state at the desired location. Once expanded, catheter basedequipment required for the particular surgical procedure may be passedthrough and movably operated in relation to the temporary valve.

In another embodiment of the present invention, the temporary valve maybe combined with a filter that extends distally from the temporary valveto capture debris material. In this embodiment, the temporaryvalve-filter device is preferably configured such that the open proximalend is secured to the temporary valve and the closed distal endcomprises an opening or a third valve to facilitate the passage of thecatheter equipment through the distal end of the bag and out of thetemporary valve. Additional valves may also be positioned in the filterto coincide with one or more branching arteries.

In yet another preferred embodiment of the present invention, thetemporary valve-filter device may include one or more traps within thefilter bag to trap debris material within the bag to reduce thelikelihood of debris material leaving the filter when the catheterequipment is being passed through the filter bag. The filter traps maybe comprised of one or more valves disposed within the filter bag thatare configured to open with retrograde pressure. Alternatively, thetraps may be comprised of flaps that extend inwardly from the perimeterof the bag to create a cupping effect that traps particulate matter anddirects it outwardly toward the perimeter of the filter bag. The filtertraps may be constructed of material that is capable of facilitating andfiltering antegrade fluid flow, while retaining the debris materialwithin the filter bag.

The valve-filter assembly previously described may also incorporatemultiple valves. In this arrangement, debris may be better and betterentrapped, and thus reduces the chance of debris coming out of thevalve-filter assembly. The present invention is particularly usefulwhile performing an interventional procedure in vital arteries, such asthe carotid arteries and the aorta, in which critical downstream bloodvessels can become blocked with debris material.

One benefit of the current invention is that it provides fast, simple,and quick deployment. One may deploy both the filter and temporary valvesimultaneously. The valve-filter assembly may also include a cannulationsystem at the downstream end of the filter to remove particles anddebris. The valve-filter assembly may also include a grinder for cuttingup or reducing the size of the debris. This debris, in turn, may beremoved by a cannulation system or be allowed to remain in the filter.

The valve-filter assembly is well-suited for use in minimally invasivesurgery where the valve-filter may be placed in the aorta between theaortic valve and the innominate branch or the braciocephalic branch. Insuch a configuration, the valve-filter may be put in place before thestart of surgery and function as a valve. The valve-filter may furthercollect debris and particles during removal and clean up of the oldvalve. The valve-filter may also stay in place while the new valve isput in place and until the end of the procedure to function asprotection and as a valve. A vascular filter system is well known to oneskilled in the art, for example, U.S. Pat. No. 6,485,501 issued on Nov.26, 2002.

In all of the embodiments described above, the invention may be part ofa catheter. The invention may also be assembled onto a separatecatheter. The valve-filter may also be part of a non-catheter device,placed directly into a blood vessel or other lumen. In both the catheterand non-catheter embodiments, the valve-filter may be introduced intothe body by the ways described in the following non-inclusive list:femoral artery, femoral vein, carotid artery, jugular vein, mouth, nose,urethra, vagina, brachial artery, subclavian vein, open stemotomies,partial stemotomies, and other places in the arterial and venous system.

Furthermore, in all of the embodiments described above, the filter meshof the valve-filter may be of any size and shape required to trap all ofthe material while still providing sufficient surface area for providingsatisfactory flows during the use of the filter. The filter may be asheet or bag of different mesh sizes. In a preferred embodiment, themesh size is optimized taking the following factors into consideration:flow conditions, application site, size of filter bag, rate of clotting,etc.

Radiopaque markers and/or sonoreflective markers, may be located on thecatheter and/or the valve-filter assembly. An embodiment of thevalve-filter catheter is described having an aortic transilluminationsystem for locating and monitoring the position and deployment state ofthe catheter and the valve-filter assembly without fluoroscopy.

Additionally, visualization techniques including transcranial Dopplerultrasonography, transesophageal echocardiograpy, transthoracicechocardiography, epicardiac echocardiography, and transcutaneous orintravascular ultrasoneography in conjunction with the procedure may beused to ensure effective filtration.

Alternatively, or additionally, the material of the filter screen ineach embodiment of the filter catheter may be made of or coated with anadherent material or substance to capture or hold embolic debris whichcomes into contact with the filter screen within the valve-filterassembly. Suitable adherent materials include, but are not limited to,known biocompatible adhesives and bioadhesive materials or substances,which are hemocompatible and non-thrombogenic. Such material are knownto those having ordinary skill in the art and are described in, amongother references, U.S. Pat. Nos. 4,768,523, 5,055,046, 5,066,709,5,197,973, 5,225,196, 5,374,431, 5,578,310, 5,645,062, 5,648,167,5,651,982, and 5,665,477. In one particularly preferred embodiment, onlythe upstream side of the elements of the filter screen are coated withthe adherent material to capture the embolic material which comes incontact with the upstream side of the filter screen after entering thefilter assembly. Other bioactive substances, for example, heparin orthrombolytic agents, may be impregnated into or coated on the surface ofthe filter screen material or incorporated into an adhesive coating.

In a preferred method, blood is filtered during cardiac surgery, inparticular during percutaneous valve surgery, to protect a patient fromembolization. In this method, the valve-filter is positioned in theaorta between the aortic valve and the inominate branch, where itfilters blood before it reaches the carotid arteries, brachiocephalictrunk, and left subclavian artery. The valve contains the embolicmaterial and foreign matter dislodged during the surgery and alsoprovides a temporary valve for use during valve surgery. Such a methodmay be utilized both on and off pump. Such a method may also be utilizedfor aortic, mitral, and pulmonary valve surgery and repair.

Although this invention has been exemplified for purposes ofillustration and description by reference to certain specificembodiments, it will be apparent to those skilled in the art thatvarious modifications and alterations of the illustrated examples arepossible. Numerous modifications, alterations, alternate embodiments,and alternate materials may be contemplated by those skilled in the artand may be utilized in accomplishing the present invention. Any suchchanges which derive directly from the teachings herein, and which donot depart from the spirit and scope of the invention, are deemed to becovered by this invention.

1. A valve assembly comprising: a replacement valve comprising an inflowannulus, an outflow annulus, and a plurality of leaflets; and acollapsible and expandable anchoring structure; said anchoring structurebeing dimensioned to extend longitudinally from an attachment locationnear the inflow annulus of a valve sinus to an attachment locationwithin a sinus cavity; said anchoring structure further comprising aflared inflow rim and a plurality of flexible vertical posts extendingfrom the inflow rim in a direction toward said outflow annulus of saidvalve.
 2. The valve assembly of claim 1, wherein said inflow annulus isscalloped.
 3. The valve assembly of claim 1, wherein said flared inflowrim comprises a ring configured in an undulating pattern.
 4. The valveassembly of claim 1, wherein said flexible vertical posts are configuredto coincide longitudinally with the sinus commissural posts.
 5. Thevalve assembly of claim 1, wherein said flexible vertical posts furthercomprise a diamond-shaped element.
 6. The valve assembly of claim 5,wherein said flexible vertical posts flex inwardly at back flowpressure.
 7. The valve assembly of claim 1, wherein said valve ispositioned internally to said anchoring structure.